This invention relates to the radioimmunoassay of migration inhibitory factor and related mediators produced by human lymphocytes.
Migration inhibitory factor (MIF) is a macromolecular product that inhibits macrophage migration. The biochemical nature of MIF produced by sensitized lymphocytes has been elucidated by David, Proc. Nat. Acad. Sci. U.S. 56, 72-77 (1966); Fed. Proceedings 30, 1730-35 (1971); and by Rocklin, J. Immunol. 112, 1461-66 (1974).
Sensitized lymphocytes are believed to play an important role in a number of biological reactions including delayed hypersensitivity, resistance to certain microorganisms and tumors, rejection of transplant tissues and even autoimmune diseases. These sensitized lymphocytes, when stimulated by antigens or mitogens, synthesize and secrete MIF and other soluble mediators.
Since MIF and MIF-like substances are believed to play an important role as mediators of cellular immunity, their evaluation or quantitation is of considerable interest. Various techniques currently are available for evaluating these mediators produced by lymphocytes. The methods are all complicated in vitro bioassay procedures which involve measuring the areas of cell migration in the presence and absence of the mediators. [See Clausen, Acta Allergol. 26, 56-80 (1971); id. at 28, 145-58 and 351-64 (1973)]. Consequently, they are unsuitable for routine hospital or clinical laboratory use and generally are performed only in basic and applied research laboratories. A non-bioassay method for the determination of MIF and MIF-like mediators would have significant advantages over the current bioassay methods insofar as it would be less cumbersome for clinical laboratory use and would be more quantitative.